Thanks Gary for the info. Yours and other info I have seen means my mid 29 should also have the bottom rivets and doubled straps at the bottom.
CHuDWah,
I am very confident the bottom rivets and doubled straps did NOT happen when the square cab was changed to the more modern rounded cab in mid 1930. I have seen original 29 pickups that have the extra rivets on the tailgate. I just wasn't sure when Ford went to the extra two rivets and the doubled straps. It sure seems that only some 1928 pickups (early maybe) and repro tailgates don't have the rivets at the very bottom. However most repro tailgate I have seen do have the doubled straps. I have attached a picture of a typical repro tailgate - note there are NO rivets at the bottom of the straps, but the straps ARE doubled over.